Apparatus for testing subjects for response to stimuli are known in the prior art. Reference may be had to U.S. Pat. No. 2,678,692 to Ranseen or to U.S. Pat. No. 3,869,812 to Arakelian et al. However, none of presently known apparatus are able to provide such selection and programming of stimuli and desired response(s) as to be useful, both to the medical profession for diagnostic purposes and to other disciplines for less technical purposes.